Drive spring arrangement for watch movement using two barrels



1969 H. KOCHER 3,479,813

DRIVE SPRING ARRANGEMENT FOR WATCH MOVEMENT USING 'IWO BARRELS FiledOct. 25, 1967 5 Sheets-Sheet 1 INVENTOR HANS KOCHER 40,802): a \Y/wu.

ATTORNEYS Nov. 25, 1969 H. KOCH ER 3,479,813

DRIVE SPRING ARRANGEMENT FOR WATCH MOVEMENT USING TWO BARRELS Filed Oct.25, 1967 5 Sheets-Sheet 2 INVENTOR HANS KOCHER ATTORNEYS H. KOCHER Nov.25, 1969 DRIVE SPRING ARRANGEMENT FOR WATCH MOVEMENT USING TWO BARRELSFiled Oct. 25, 1967 5 Sheets-Sheet 5 HANS KOCHER (L /Ma WW4 ATTORNEYSNov. 25, 1969 H. KOCHER 3,479,813

DRIVE SPRING ARRANGEMENT FCR WATCH MOVEMENT USING TWO BARRELS Filed Oct.25, 196'? 5 Sheets-Sheet 4 FIE. 5

INVENTOR HANS KOCHER @[Mc f MM ATTORNEYS H- KOCHER Nov. 25, 1-969 DRIVESPRING ARRANGEMENT FOR WATCH MOVEMENT USING "IWO BARRELS Filed Oct. 25,1967 5 Sheets-Sheet 5 FILE. 7

INVENTOR HANS KOCHER (QR Me 5 ATTORNEYS United States Patent US. Cl.5859 14 Claims ABSTRACT OF THE DISCLOSURE A watch movement having twoseparate drive springs housed in respective barrels which are mountedabout parallel rotative axes, both said barrels being drivinglyconnected to the center-wheel runner of the time train, and including aself-winding train wherein the ratchet wheels of both barrels areconnected to a third step-down runner in the winding train.

This invention relates to an improved power spring arrangement formechanical watch movements of the type wherein the power spring means isrequired to drive the oscillating balance member at frequencies in theorder of 30,000 times per hour and higher.

In watches it is known that the time keeping accuracy can be increasedby increasing the oscillations of the balance mechanism above thecustomary 18,000 per hour to values in the order of 30,000 and more perhour. This results in an increase in accuracy at the cost, however, ofincreased energy consumption by the movement. Furthermore, the drivingtorque required in such circumstances is in the order of two or threetimes that required in conventional wrist watches. Such a higher drivingtorque in the rotative members necessitates correspondingly larger andsturdier bearings for said members, especially for the first runner ofthe time train, and for the last runner of the winding train in theevent that a self-winding watch is involved.

Heretofore it has been found that if the first runner of the step-uptrain is a center-wheel runner upon whose shaft is carried the cannonpinion to which the minute hand is fastened, and if the drive spring ishoused in a customary barrel, it is impossible to have a movement, andespecially a wrist watch movement, of small enough dimensions inconformity with modern day requirements while still providing bearingswhich are sufficiently robust to withstand the higher torques applied tothe rotative elements. This disadvantage prevails even if a self-windingweight which is pivoted coaxially with the centerwheel runner isomitted.

Watch movements are well known comprising two barrels, each housing aseparate power spring of which one drives the time train of the movementwhile the other powers an alarm sounding mechanism. It has been proposedto modify this concept so that both springs are utilized to power thetime gear train whereby the running I time of the movement is prolongedto a'considerable extent. In such an arrangement, the individual barrelswould turn more slowly than in those movements using a single time trainpower spring, and the same applies to the first runner of the step-upgear train which is driven simultaneously by both barrels.

The use of two barrels, mounted about parallel axes relative to eachother, could provide double the driving torque without disturbing thesymmetrical disposition of parts as would occurif a single equivalentlarge barrel were used instead of two smaller ones. In instances where-3,479,813 Patented Nov. 25, 1969 in two barrels are employed, the timetrain can comprise five runners and the first runner thereof may belocated in front of the center wheel. In other instances, the traincomprises only four runners and the minute-indicating member isindirectly driven. Furthermore, it has been contemplated to employ anoscillating weight to achieve a self-winding of the two springs.

An object of this invention is to provide a high torque watch movementwhose size is within the limitations of modern day standards.

A specific object is to provide an improved watch movement whose balancemember oscillates more than 30,000 times per hour.

A further object is to provide a novel power spring arrangement wherebythe bearing loads imposed upon the center-wheel runner and upon thewinding train runner of the movement are considerably reduced relativeto conventional power spring arrangements.

A further object is to provide a larger power spring means providing anincreased reserve running time, especially for self-winding watches,without the larger power spring means disturbing the symmetricalarrangement of parts relative to the movement central axis.

A further object is to provide a novel arrangement of power spring meansand the winding train therefor, in a self-winding watch, whicharrangement is highly responsive to even small imbalances in the windingweight whereby the spring means is wound pursuant to even slightmovements of the wearers wrist.

The foregoing and other objects of this invention are generally realizedthrough the provision of two separate drive springs, each housed in arespective barrel, the gear teeth of which are in engagement with acommon single runner which is the first runner of the step-up gear trainwhich drives the balance oscillator, said first runner being thecenter-wheel runner. As will be subsequently explain in detail, such anarrangement results in lower stresses being imparted to the bearings ofthe first wheel runner as compared to having an equivalent torquetransmitted from a single barrel, and, consequently, the bearings may beof corresponding smaller size thereby resulting in a smaller watchmovement.

The invention will be described in detail with reference to a preferredembodiment which is shown in the accompanying drawings wherein likereference characters in the several views denote like parts, andwherein:

FIGURE 1 is a top plan view of the movement according to this invention,various bridges and runners having been omitted for purposes of clarity;

FIGURE 2 is a view analogous to FIGURE 1 excepting that only the bridgeof the self-winding mechanism has been omitted for clarity;

FIGURES 3 to 5 are sectional views taken along lines IIIIII, IVIV, andVV, respectively, in FIGURE 2;

-FIGURES 6 and 7 are vector force diagrams related to bearings ofrespective runners of the movement.

With reference to FIGURES 1 and 3, the movement of this inventioncomprises two spring barrels 5 and 6, a center-wheel runner 77', a thirdwheel runner 88', a fourth wheel runner 9-9, an escape wheel 10 and abalance 11 all of which are mounted between circular plate 1 andrespective ones of the time train bridge 2, the cock 3, and the barrelbridge 4. The escape lever 12 is pivoted in and between plate 1 andescape bridge 13 which is itself fastened to plate 1 and extends belowthe balance 11. An intermediate bridge 15 extends radially between thebarrels 5 and 6 and above their respective gear teeth and supports abearing 14 which constitutes the upper bearing for center-wheel runner7.

The ring gears 5 and 6' of the respective barrels 5 and 6 both engagethe pinion 7 of the center-wheel runner and rotatively drive it at therate of one revolution per hour. The step-up gear ratio between thecenter-wheel runner 7-7 and the third wheel runner 8-8 as well as theratio between the third wheel runner and the fourth wheel runner are theusual ratios. n the other hand, the gear ratio between the fourth wheelrunner 9-9 and the pinion 10 of the escape wheel runner 10-10 is 100 to7. Furthermore, the escape wheel 10 has twenty-one teeth so that thebalance 11 must oscillate 36,000 times per hour in order for the timetrain to turn at the conventional speed.

In FIGURE 3 it is seen that the center-wheel runner 7-7 comprises ahollow staff 16 through which extends the staff 17 of the fourth whe'elrunner 9-9, a cannon pinion 18 being coaxially mounted externally aroundan end portion of said staff 16. The cannon pinion 18,. in turn, ishoused in the conventional manner in an opening in plate 1 and mesheswith a minute Wheel 20 which is rotatively mounted on stud 21 which isfastened in plate 1. The minute wheel 20, in turn, meshes with anddrives the hour wheel 22 which is coaxially mounted relative to thecannon pinion 18. The fourth wheel runner 9-9 is pivoted in twobearings, one of which 23 is mounted in bridge 15 and the other of which24 is mounted in bridge 2.

A self-winding mechanism for winding the respective springs housed inbarrels 5 and 6 is shown in FIGURES 2 and 4 and comprises a weight 25rigid with shaft 26 and eccentrically disposed relative to the axis ofsaid shaft. Shaft 26 is rotatively mounted in two bearings, one of which27 is mounted in bridge 2 and the other of which constitutes an opening28 extending through bridge 29. Bridge 29 serves as a bridge for theselfwinding mechanism and is secured to bridge 2. Shaft 26 is rigid witha first pinion 30 of the winding train, pinion 30 being coaxial with thecenter-wheel runner 7-7. The first pinion 30 meshes with an intermediatewheel 31 which, in turn, engages the two wheels 32 and 33 of a reverserassembly whose wheel 33 constitutes part of a first step-down runner33-34, wheel 33 being rigid with pinion 34 which drives a secondstep-down runner 35 which is rotatively mounted about a cylindrical bossextending from plate 1 below barrel 6. Runner 35 drives intermediatewheel 36 which is coaxial with barrel 6, wheel 36 driving thirdstep-down runner 37-38 whose pinion 38 engages the ratchet wheel 39which is carried on the end of staff 40 of barrel 6 at the end oppositeto plate 1.

It should be noted that the staffs of both runners, 33-34 and 37-38, arepivotably supported at their opposite ends in plate 1 and in bridge 29of the self-winding mechanism, while the respective staffs of wheels 31and 32 and the shaft 26 of oscillating weight 25 are pivotably supportedin the time train bridge 2 and in bridge 29.

The inclusion of three step-down runners: 33-34, 35, and 37-38, providesfor a high step-down ratio from the oscillating weight 25 to the windingbarrels 5 and 6,

whereby even a slight imbalance in said weight is sufficient to overcomethe resistive torque of the ratchet wheels 39 and 41 in order for saidweight to simultaneously wind the springs housed in said barrels.

The movement further comprises a winding stem 42 (FIGURE 5) whichextends between the plate 1 and the barrel bridge 4, said stem beingrotatively mounted between adjacent portions of said plate and bridge.Stem 42 is connectable to the other movement parts via a conventionaltransmission means comprising a clutch pinion 43 and a winding pinion44, whereby said stern can either wind the power springs or set theindicating hands on the watch dial. In order to set the hands, a settinglever (not shown) brings the clutch pinion 43 into engagement with afirst hour setting wheel 45 which, in turn, actuates a second orintermediate hour setting wheel 46 which is in engagement with theminute wheel 20. In order to wind the power springs, the clutch pinion43 engages pinion 44 which drives the crown wheel 47 which, in turn, isrotatively mounted about a boss 48 and is held thereon by a screw member49. Boss 48 includes a notch 50 (FIGURE 2) which permits displacement ofcrown wheel 47 whereby said ratchet wheel 41 can rotate freely of crownwheel 47 in a clockwise direction, relative to FIG- URE 2, when saidratchet wheel is driven by the pinion 38. On the other hand, when stem42 is actuated so as to turn crown wheel 47 counterclockwise, said crownwheel 47 is held engaged with ratchet wheel 41 whereby rotation of stem42 is transmitted through elements 47, 41. and 38 to ratchet wheel 39.

In FIGURE 2 it will be noted that the axes of the staffs of barrels 5and 6 and the axes of the staffs of runners 30 and 37-38 (runner 30being along the central axis of the movement and runner 37-38 being therunner of the self-winding mechanism) are located at the corners of asubstantially symmetrical diamond-sl1aped polygon, with the axes ofrunners 30 and 37-38 lying along an axis of the polygon which isperpendicular to and midway along an axis of the polygon which connectsthe rotative axes of barrels 5 and 6.

The importance of this arrangement is demonstrated in FIGURE 6 whereinthe axes of barrels 5 and 6 are respectively denoted as 54 and 55 andthe axis of runners 37-38 is denoted as 56, with the arrows 51, 52, and53 indicating the rotative directions of the barrels and of the runner38.

When winding weight 25 pivots about the axis of shaft 26, a windingtorque is transmitted through the aforedescribed winding train tointermediate winding runner 36 which is coaxial with barrel 6, saidrunner 36 thereby being urged to turn in the direction of arrow 52 (FIG-URE 6). This torque is, in turn, transmitted from runner 36 to wheel 37and to pinion 38 which is interconnected with wheel 37 via a commonstac. The laws of equilibrium of forces require that this torque becounterbalanced by an equal and opposite torque representing the sum ofthe resistance torques which are exerted upon pinion 38 by the tworatchet wheels 39 and 41 which are acted upon equally by each one of thepower drive springs.

The direction of the tangential driving force exerted by runner 36 uponwheel 37 is indicated by arrow 57, the value of which will hereafter bedenoted F The consequent rotative torque M imparted by F upon runner37-38 is given by the equation M=F R wherein R is the radius of wheel37.

The resistance torque which counterbalances M is developed by thetangential resistance forces F and F imposed upon pinion 38 by the tworatchet wheels 39 and 41, respectively. In FIGURE 6 the resistanceforces F and F have been drawn along radial lines extending from therotative axis of runner 37-38 for the purpose of drawing a vectordiagram. In any event, the lines F and F are each parallel to respectivetangent lines which pass through the points of contact between pinion 38and each of the ratchet wheels 39 and 41 and necessarily, therefore,lines F and F are each respectively perpendicular to straight linesextending between axis 56 and axis 54 and between axis 56 and axis 55.

Forces F and F are equal to each other in amplitude and conform to theequation wherein r is the radius of pinion 38.

Force F acts in the plane of wheel 37 while forces F and F act in theplane of pinion 38. The bearings which rotatively support runner 37-38are subjected to hearing loads which are proportional to the magnitudeof the respective tangential forces F F and'F In the plane of wheel 37,the bearing load will be substantially equal to force F while in theplane of pinion 38 the bearing load will be substantially equal to Freswhich is the vectorial sum of F and F whereby as is evident from thevectorial relationship shown in FIGURE 6.

The herein disclosed arrangement, therefore, reduces to a considerableextent the bearing load in the plane of the winding pinion 38 comparedto what it would be if only one power spring, equivalent in strength tothe two described herein, were employed. If only one equivalent springwere employed, the bearing load in the plane of the winding pinion 38would be equal to F +F or2F or 2P (since F =F as compared to 0.7F whichresults from the arrangement shown herein.

Even if only one spring were employed which was only equivalent to oneof those referred to herein, the bearing load in the plane of pinion 38would be equal to 1.0F this still being considerably higher than thevalue of 0.7F which the present invention provides even with twice thespring power.

A further important feature, however, derives directly from the factthat forces F and F act in one plane which is axially spaced away fromthe plane in which force F acts. Since the respective forces act indifferent planes, they could establish a force couple between themselvestending to tilt the axis of runner 37-38. In other words, with referenceto FIGURE 4, assuming that force F had a component acting towards theright in the plane of wheel 37 and assuming that force F.,, had acomponent acting toward the left in the plane of pinion 38, this wouldestablish a force couple tending to turn or tilt the entire runner 37-38in a counterclockwise direction.

Relating the principle of the force couple to the instant situation, itis seen that if the total force acting in the plane of pinion 38 wererelatively high, the tilting tendency upon runner 37-38 would beproportionally greater than if said force were relatively lower.

The bearings for runner 37-38 can, therefore, be considerably reduced insize for an arrangement in accordancewith this invention relative toheretofore known power spring arrangements.

Furthermore, the thickness of bridges can be reduced as well as theoverall dimensions of various bearing elements. The overall dimensionsof the movement are correspondingly reduceable to acceptable standardsnotwithstanding the fact that the power spring means is capable ofstoring a relatively high reserve of power, namely, such as is requiredto obtain 36,000 oscillations per hour in the oscillating assembly. Thehigh power reserve is especially important in self-winding watches whichmust allow for periods during which the wearer may perform few windingmovement with its wrist.

With regard to the self-winding mechanism, the arrangement disclosedherein permits said mechanism to have a very high step-down ratio, thisassuring effective winding even with very small wrist movements,notwithstanding the high value of torque provided by the two powersprings, said torque being in the order of 1500 to 2000 g./mm.

FIGURE 7 is analogous to FIGURE 6 but is referred to the forces actingupon the center-wheel runner 7-7. The ring gear on each barrel 5 and 6engages pinion 7' and each ring gear exerts a tangential force F and Fupon said pinion 7, with said barrels 5 and 6 turning in the directionsof arrows 51 and 52. The torque imposed upon pinion 7' by forces F and Pis counterbalanced by a resistance torque which results from a forceexerted upon wheel 7 by pinion 8' of the third wheel runner 8-8.

The tangential force which acts in the plane of wheel 7 can be neglectedsince it is quite low relative to the forces acting at the level ofpinion 7' as a result of being reduced in the same ratio as that betweenthe diameter of wheel 7 relative to pinion 7'.

The tangential forces acting in the plane of pinion 7', however, conformto the equation wherein r; is the radius of pinion 7 By vectorialanalysis, the resultant Of F +F =Fres=O.83F =0.83F

It is seen, therefore, that the reduced bearing load conditionspreviously described with reference to the runner 37-38 are alsoanalogously applicable to center-wheel runner 7-7 whereby the bearingsof this runner may be correspondingly smaller than would be required inconventional watch movements.

The details described herein with reference to a preferred embodimentare given by way of illustration and not for purposes of limitation.

What is claimed is:

1. A watch movement comprising a power spring means and a balanceoscillator means, a time train extending from said spring means to saidoscillator means, said spring means comprising two springs each housedin a separate barrel, each barrel being directly engaged with a firststep-up runner of said time train, said first step-up runner being thecenter-wheel runner, a self-winding mechanism comprising a windingweight and a step-down winding train connecting said weight to each oftwo ratchet wheels which are respectively associated with said powermeans, the last step-down runner in said winding train including awinding pinion in direct engagement with both said ratchet wheelssimultaneously.

2. The movement of claim 1, wherein said winding weight includes a staffwhich is coaxial with said centerwheel runner.

3. The movement of claim 1, wherein the vectorial resultant of thecombined tangential forces exerted by said ratchet wheels upon saidpinion of said last step-down runner is equal to 0.7 times either one ofsaid forces, said tangential forces being equal to each other.

4. The movement of claim 1, wherein the rotative axes of said barrelslie at opposite ends of a first straight line and the rotative axis ofsaid center-wheel runner and of said last step-down runner lie atopposite ends of a second straight lines, said first and second straightlines perpendicularly bisecting each other.

5. The movement of claim 1, said barrels each being supported onrespective barrel shafts, both said shafts being rotatively mounted incommon bridges.

*6. The movement of claim 1, including a manual winding means forwinding said springs.

7. The movement of claim 1, wherein said winding train comprises threestep-down runners.

8. The movement of claim 7, wherein the first of said step-down runnersincludes a wheel which is part of a reverser gear means, a pinion rigidwith said weight and engaged with an intermediate wheel which engagessaid reverser gear means.

9. The movement of claim 8, wherein the second of said step-down runnersincludes a pinion which engages an intermediate wheel which is coaxialwith one of said barrels and which in turn engages the wheel of thethird step-down runner which is the last of said step-down runners.

10. A watch movement comprising a power spring means and a balanceoscillator means, a time train extending from said spring means to saidoscillator means, said spring means comprising two springs each housedin a separate barrel, each barrel being directly engaged with a firststep-up runner of said time train, said first step-up runner being thecenter-wheel runner, said center-wheel runner including a pinion indirect engagemet with both said barrels and a gear wheel in drivingengagement with a third wheel runner which in turn is in drivingengagement with a fourth wheel runner, said fourth wheel runner beingcoaxial with said center-wheel runner.

11. The movement of claim 10, wherein said centerwheel runner gear wheelextends in a plane below the lower face of the barrels and wherein saidfourth wheel runner includes a gear wheel which extends in a plane abovethe upper face of said barrels.

12. The movement of claim 11, including an intermediate bridge extendingradially between the barrels at a level between the upper and loweraxial ends of said barrels, a bearing in said bridge rotativelysupporting said fourth Wheel runner coaxially with said center-wheelrunner.

13. A watch movement comprising a power spring means and a balanceoscillator means, a time train extending from said spring means to saidoscillator means, said spring means comprising two springs each housedin a separate barrel, each barrel being directly engaged with a firststep-up runner of said time train, said first step-up runner being thecenter-wheel runner, said barrels both being engaged with a pinion ofsaid center-Wheel runner in a common plane, the vectorial resultant ofthe combined tangential forces exerted by said barrels upon saidcenter-wheel runner being equal to 0.83 times either one ReferencesCited FOREIGN PATENTS 86,219 8/ 1920 Switzerland. 141,602 8/ 1929Switzerland. l/ 1932 Switzerland.

RICHARD B. WILKINSON, Primary Examiner GEORGE H. MILLER, JR., AssistantExaminer U.S. C1. X.R. 58-86 22 3 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION 3,479,813 Dated November 25, 1969 Patent NoInventor (s) HANS HER It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 4, line 36, "stac" should read staff Column 5, line 51,"movement" should read movements SIGNED AND SEALED JUN 2 3 197 Amt:

Edward M. Mar, Ir. mm E m AM 0m Oomissiomr or I'M- uts

